The present invention relates to an edge ring for a press roll.
In roll presses, the pulp suspension is generally dewatered between two press rolls. On their peripheries, these press rolls are equipped with perforated shell plating on which, if appropriate, cloth-type mesh can be placed. Water is pressed into the roll through the plating and, if used, the cloth-type mesh, and the water then exits through channels in the interior of the press rolls. At the edges of the press rolls edge rings are screwed in place along the peripheries of the end surfaces of the rolls. These edge rings function as sealing surfaces in the end seal on the press roll, as well as places where the cloth-type mesh, if used, can be attached. The wear surfaces on the edge rings wear down due to the fact that fibers pass through the seal while the pulp is being pressed, and since the edge rings cannot be repaired by welding due to risk of heat stress and the like. Each edge ring must therefore be considered a wear part and replaced. This is a complicated and time-consuming procedure which requires lifting the entire roll out of the roll press.
An object of the present invention is thus to solve the problem of replacing worn edge rings by providing an easily replaceable edge ring that requires a minimum of personal resources, tools and lifting equipment.
In accordance with the present invention, this and other objects have now been realized by the invention of apparatus for attachment to a press roll having an end including an edge and a peripheral surface, the apparatus comprising an edge ring extending around the edge of the press roll, the edge ring comprising a plurality of edge ring sectors dividing the edge ring diametrically, the plurality of edge ring sectors including a radial outer portion and a radial inner portion, the radial outer portion including a hook-shaped portion for forming a cap joint with the edge of the press roll. In a preferred embodiment, the hook-shaped portion of the edge roll includes an axially extending portion which forms a smooth continuous surface with the peripheral surface of the press roll and a radially extending portion for mating with the edge of the press roll.
In accordance with a preferred embodiment of the apparatus of the present invention, the radial inner portion of the edge roll includes a threaded joint portion for attachment to the end of the press roll. In a preferred embodiment, the end of the press roll includes an inwardly facing shoulder, and the edge ring includes an outwardly facing peripheral shoulder for contacting the inwardly facing shoulder of the press roll, the outwardly facing peripheral shoulder of the edge roll being located radially outwardly with respect to the threaded joint portion of the edge roll.